Anyone familiar w/Alcan primers

[Blue68f100]

While I can’t recall or quote references, In my 45 years of hand loading, reading manuals and various publications on the subject, I’ve always read that reducing a starting load by 5 or even 10% is a safe way to start. Published data of decades ago can be much different than published data of today. It even varies between different manuals for the same caliber.
Perhaps those with more technical knowledge can expand on this.
The Op wants to use components that currently published data is no longer available for. The component has changed, it’s an unknown value now.
Reducing the starting load IMO is a safe start.

That is only done when MAX load is only given. Then you needed to read all the notes on the powder since some were only 3% or none.

I've been loading for 45+ yrs and this is the way it has always been. You apparently got something mixed up.

Now there are times where you start at min and work down. This is done when your are trying to workup a BE load that's soft shooting so you can control the recoil impulse for the follow up shots.

 

[whughett]

The cci 200 are good to go so that leaves the Alcan max-fire LRP. Some stuff on internet says to treat like magnum primers. Is that true? Should i not use them for 243?

I will be loading speer 85 gr btsp over imr 4895 (havent determined starting point yet) with win brass.

My comment were based on the question as posted above. Assuming the OP is using some manuals loading data that uses standard primers and he wants to use an out of date magnum primer why would reducing that starting load by 5% be an issue.

 

[Juiceking]

Lots of good replies thank you. For clarity my Alcan primers are regular primers not magnum primers. So i wont be loading 5% below printed min. However this is the first time in my short reloading career that i don't have clear load data.

I will be loading speer 85gr BTSP over imr 4895 w/col of 2.637 for win model 70 .243.
For load data im using:
Hogdon 2020 mag 85 gr bar tsx 34.6-36.8
Sierra book 85 gr spitzer & HPBT 31.8-37.8
Lyman 49th 85gr HPBT 33.0-38.0
Speer online 85gr spitzer HPBT 37.5-41.5

So i haven't decided yet but probably going to start around 33.0gr but still doing some research.

Oh and of course after sizing, trimming and priming i put brass in my rifle and couldn't close the bolt. Wonderful already screwed up!